<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
		/*多个class ；class 之间使用空格。这样可以提取公共的样式*/
			 .color{
				background-color: blue;
			} 
			.width{
				width: 200px;
				height: 200px;
			}
			.width02{
				width: 400px;
				height: 400px;
				margin-top: 10px;
			}
			/*body>div{
				background-color: red;
			}*/
		</style>
	</head>
	<body>
		<div class="width color">
		</div>
		
		<div class="width02 color">
		</div>
		
		<p class="p color">123</p>
		
	</body>
</html>
